;colony/science / Weather & the Earth
☂ Weather & the Earth
Weather & the Earth
Storms, seasons of the sky, and the planet doing its daily work overhead.
Read it your way
Every answer here is written twice. Flip the switch and the page rewrites itself.
Try it now · Plate 33
Why does thunder follow lightning?
Trigger the flash, count along with the stopwatch, and catch the boom.
PLATE 33 · THE THREE-SECOND KILOMETRE
Storm distance 3.4 km away
Slide the storm closer and the gap shrinks. (Time runs 3× here so you wait less.)
Flash → boom gap
9.9s
The rule of thumb
10 s ≈ 3 km
Light is so fast it arrives the instant the bolt strikes. Sound is a jogger — about
1 km every 3 seconds. So when you see a flash, start counting:
one-thousand, two-thousand… divide by three and you know how many kilometres
away the storm is. Shrinking counts mean it's coming your way.
Every question
Weather & the Earth, answered twice.
Plate 33Open → Why does thunder follow lightning? The flash and the bang happen at the same instant. They just travel home at very different speeds — and the gap between them is a free measuring tape. Plate 40Open → What is the greenhouse effect? Earth lets sunlight in easily but lets heat back out only grudgingly — and a few trace gases set how grudgingly. Thicken the blanket and the whole planet warms. Plate 44Open → How do planes fly? Forget the textbook story about air racing over a longer top surface. A wing flies for the same reason a swimmer moves: it throws something backward — in this case, a river of air, straight down. Plate 45Open → The Doppler effect A passing ambulance doesn't change its siren — but you hear it leap high then drop low. The sound the source makes and the sound you receive are two different things. Plate 90Open → How do hurricanes form? A hurricane is a heat engine, and its fuel is warm seawater. Plate 91Open → Why do clouds float? A fair-weather cloud can weigh as much as a hundred elephants. It floats anyway. Plate 92Open → How do earthquakes happen? The ground that shakes for thirty seconds spent thirty years getting ready. Plate 134Open → Why is the ocean salty? Rain is fresh and rivers taste fresh, yet the sea they feed is salty. The salt has to come from somewhere, and it does — one tiny mineral sip at a time. Plate 135Open → Why do snowflakes have six sides? Every snowflake is different, the saying goes — and yet every one has exactly six sides. Both halves of that are true, and the reason is the same reason. Plate 136Open → What makes the wind blow? Wind feels like the air deciding to move, out of nowhere. It is really air doing the most ordinary thing there is — sliding downhill, from a crowded place to an emptier one. Plate 137Open → How does a volcano erupt? A volcano looks like the planet boiling over. The real trigger is closer to a shaken bottle of fizzy drink — gas that was hiding in the liquid, suddenly let go. Plate 138Open → Why does it rain? Clouds look soft and dry, yet they hold tonnes of water and sometimes drop it on your head. The water was there all along — it just had to gather into drops heavy enough to fall. Plate 162Open → What is the dew point, and why does dew form? Warm air holds invisible water like a sponge; cold air can hold far less. Cool the air to its dew point and the sponge is full — the water has to come out, beading on the cold grass as dew. Plate 166Open → What causes a mirage on a hot road? That shimmering puddle on the road ahead is a patch of sky, bent back up to your eye by a thin layer of scorching air hugging the tarmac. There was never any water there.
— ;colony